You can easily check and understand its a typo.
Let A = {1,2},
B = {3,4}
C = {3}.
AX(B-C) = (1,4) (2,4)
AXB 1,4 2,4 1,3 2,3, and BXC = 3,3 4,3.
I hope I'm not making a full of myself and your doing things that are much more complicated then what I just said :)